Fire extinguisher

ABSTRACT

The specification discloses a fire extinguisher comprising a closed container having a fire extinguishing gas under pressure located within the container. Perforating means are located on the exterior of the container for perforating its wall at least at one selected position, when actuated, to form an opening through the wall to allow the fire extinguishing gas to pass out through said opening. Heat sensitive means is provided for actuating the perforating means to form the opening in the wall in the presence of undesired temperatures. In one embodiment, the perforating means comprises a shaped explosive charge while in the other embodiment, the perforating means comprises a cutting means having a sharp edge which is driven into the container wall by an explosive charge.

O 1 United States Patent 11 1 1111 3,874,458

Williams Apr. 1, 1975 1 FIRE EXTINGUISHER Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Michael Mar 75 l l nvemor $25?" A wllhams Fort worth Attorney, Agent, or F1rmWofford, Felsman, Falls &

Zobal [73 l Assignee: Pyro Control. Inc.. Fort Worth,

57 ABSTRACT [22] Filed: Nov. 12, 1 973 The specification discloses a fire extinguisher comprising a closed container having a fire extinguishing gas [2]] Appl' 4l4642 under pressure located within the container. Perforatin'g means are located on the exterior of the container [52] US. Cl 169/59, 169/65, 169/28 for perforating its wall at least at one selected posi- [51] Int. Cl. A62c 35/02 tion, when actuated, for form an opening through the [58] Field of Search 169/2 R, 26, 28, 30, 59, wall to allow the fire extinguishing gas to pass out 169/60, 65 through said opening. Heat sensitive means is provided for actuating the perforating means to form the [56] References Cited opening in the wall in the presence of undesired tem- UNITED STATES PATENTS peratures. In one embodiment, the perforating means 1 708 869 4/1929 Buddecke 69/28 comprises a shaped explosive chargewhile in the other 224411011 5/1948 Dodelin .31: III 1 69/26 X embodiment the Perforating means Comprises a 2581.324 1/1952 Hartzell t 169/26 ting means having a Sharp edge which is driven into 2.841228 7/1958 Porterfield 169/26 X the COntainer wall by an explosive charge. 1604.51 1 9/1971 Griffith et a1. 169/28 3,762,479 10/1973 Fike, Sr. et al. 169/31 R X 3773.111 11/1973 Dunn 169/33 X 2 Claims, 10 Drawing Figures PATENTEB APR 1 1975 SHEET'EQfZ FIRE EXTINGUISI-IER BACKGROUND OF THE INVENTION This invention relates to a fire extinguisher employing explosives and a fire extinguishing gas under pressure which may be actuated'automatically upon occurrence of a fire or which may be actuated by remote control means.

SUMMARY OF THE INVENTION The fire extinguisher comprises a closed container having a gas confining wall, a fire extinguishing gas under pressure located in the container, perforating means located on the exterior of the container for perforating said wall at least at one selected position when actuated to form an opening through said wall to allow said fire extinguishing gas to pass out through said opening, and heat sensitive means for actuating said perforating means to form said opening in said wall in the presence of undesired temperatures.

In one embodiment, the perforating means comprises an explosive charge located on the exterior of the container wall and shaped to cause perforation of the wall when actuated by a fuse means. In this embodiment, preferably a plurality of the shaped charges are located at spaced positions around the exterior of said wall. A firetrain extends to all of the spaced charges whereby they may all be actuated substantially simultaneously to perforate the wall at a plurality of different positions to allow a desired dispersion of the fire extinguishing gas from the container.

In another embodiment, the perforating means comprises cutting means having a sharp edge for perforating the wall of the container, explosive means for forcing the edge of the cutting means into the wall for perforating the wall to form an opening and heat sensitive fuse means for igniting the explosive means in the presence of undesired temperatures. In this embodiment, preferably a plurality of cutting means are employed to form a plurality of perforations in the container wall at spaced positions to obtain a desired dispersement of the fire extinguishing gas from the container.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a partial cross sectional view of one embodiment of the fire extinguisher having an inner and outer container and employing a plurality of shaped charges for perforating the inner container containing a gas under pressure;

FIG. 2 is an end view of the fire extinguisher of FIG. 1;

FIG. 3 is a partial perspective view of the outer container illustrating apertures formed in the outer container for receiving shaped charge containers;

FIG. 4 is an enlarged cross sectional view ofa shaped charge in a ferrule having its base held between the outer container and the inner container;

FIG. 5 is a cross sectional view of a firetrain extending between adjacent shaped charges;

FIG. 6 is a partial perspective view of the fire extinguisher illustrating the firetrain extending between the shaped charges;

FIG. 7 is another embodiment of the fire extinguisher employing a plurality of cutting blades for perforating the container;

FIG. 8 is an end view of the container of FIG. 7 illustrating the cutting blades;

FIG. 9 is a side view of one of the cutting blades; and FIG. 10 illustrates the base to which the cutting blades are pivotally attached.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, the fire extinguisher is identified by reference numeral 11 and comprises an inner sealed container 13 located in an outer container 15. The inner container 13 confines a fire extinguishing gas 16 under pressure which may be du Ponts I301 Freon, sometimes referred to as Halon 1301. The inner container 13 comprises a cup shaped member 13a having a cover 1312 sealed to the end of member 13a by way of a double seam. Similarly, the outer container 15 comprises a cup shaped member 15a having a cover 15b sealed to the end of member 15a by way of a double seam. The outer container 15 has a double beaded section 17 formed around its periphery at one end 15c as illustrated also in FIG. 3. The double headed section 17 also is formed in two crossed paths at end 15c, as illustrated in FIG. 2 and which are connected with the peripherical double beaded section. As shown in FIG. 5, the double beaded section 17 comprises two spaced ridges 17a and 17 b having an indented intermediate portion 17c. Formed through the section 17 and hence through the outer container 15 between the ridges 17a and 17b are eight equally spaced apertures 19, as illustrated in FIG. 3. Also formed through the end of container 15 at the intersection of the crossed sections 17 is a single aperture 19. Extending from each aperture 19 is a container 21 having a flared end 23 which is located between the container 13 and the container 15 for holding the containers 21 in place. Deposited within each container 21 is a shaped explosive charge 25 having a conical shaped hole 25a facing the container 13 which when exploded provides what is known as the Monroe effect, a terrific piercing effect generated by the converging detonation waves coming from the container 21 driving a jet of hot gas through the container wall. Each explosive charge is connected by a fuse or firetrain located within the double beaded sections 17. When the temperature reaches a certain level, the fuse or firetrain ignites and all of the explosive charges are exploded substantially simultaneously. The fuse or firetrain and explosive charges are completely consumed upon detonation or explosion, leaving holes for the pressurized Freon to be released in all directions desired by the placement of the shaped charges.

The explosive charge employed may be lead styphnate or similar material, such as that known as Stabanate disclosed in US. Pat. No. 3,310,569. These materials have advantages due to their ability to withstand environmental temperatures and conditions encountered for a fire extinguishing device over a long period of time without degrading. When thermally ignited, they produce a quick, sharp, cool explosion which is ideally suited for purposes of the fire extinguisher as they occupy little space, require no casement, and after firing leave only minor residue. In addition, these explosives can have, but actually need, no separate fusing, as they can be fused by a protective coating of, for example, nitrocellulose. Lead styphnate has an ignition temperature flashpoint of 300C. For other primary initiating explosives which may be used, reference is made to The Chemistry of Powder and Explosives by Tenney L. Davis, pages 2 and 3.

The exterior of each of the containers 21 is covered with a thin coating 27 of lead styphnate, or other similar primary initiating explosive, which then is coated with nitrocellulose. This coating and charge serves as a fuse since it instantly detonates when contacted by flame. The firetrain comprises lead styphnate deposited between the ridges 17a and 17b of the sections 17 as illustrated at 29 in FIG. 5. The lead styphnate of the firetrain is in Contact or closely adjacent to the lead styphnate deposited on each charge container 21 whereby when one portion of the firetrain is ignited, all of the charges are substantially simultaneously exploded. Placed over the firetrain is a strip of aluminum adhesive tape illustrated at 41 for protection purposes. As shown in FIG. 6, the strip 41 extends up and over each charge. The sides of the containers 21, with their ignitable coatings, are exposed thereby making the fire extinguisher sensitive to heat or flame.

If it is desired to actuate the fire extinguisher in a controlled manner from a remote position, an electrical conductive fuse may be located within the firetrain and ignited electrically by an electrical system. A suitable fuse which may be employed is a bi-metallic fuse of the type manufactured by Pyro Fuze Corporation, an affiliate of Sigmun Cohn Corporation, 121 South Columbus Ave., Mount Vernon, N.Y. 10553. The fuse may be a single strand, for example, or a woven braid fabricated from a plurality of single strands. Each strand is formed of an outer shell of palladium and an inner core of aluminum. Fuses of this type are heat sensitive and may be ignited by a low temperature flame or the heat generated from an electrical system. As a further embodiment, the fuse employed may be of the type disclosed and claimed in my co-pending patent application Ser. No. 4 14,660, filed the same date as the present application. This fuse has a copper core coated with a fast burning substance which is wrapped with a covering of wire and nylon yarn. The covering in turn is coated with a highly flammable material. It may be ignited by heat from flame or electrically.

Referring now to FIGS. 7-10, there is disclosed another embodiment which employs a plurality of blades for perforating the wall of the container to allow the escape of the freon under pressure. This embodiment is similar to that of FIGS. 1-6, in that it employs an inner sealed container 13 containing fire extinguishing gas under pressure and which is located in an outer container 15. In this embodiment, the double beaded sections 17 are not formed on the container and the firetrain is omitted. Connected to the end 15c of the outer container 15 is a support member 51 which has a plurality of blades 53 pivotally coupled thereto. In the embodiment disclosed, the member 51 is connected to the end 150 byway of a rivet 55 and it has eight spaced slots 51a formed in its side 51b into which are fitted the eight blades 53. Each blade 53 is pivotally coupled to a pivot member or pin 57 located in the slots 51a whereby each blade may be moved to the position shown in FIG. 7 and then pivoted outwardly to the positions shown in dotted line in FIG. 7 to perforate the edge 15d of the container 15 and the edge 13d of the container 13 for releasing the freon. Although the pivot pins 57 are illustrated as square shaped in crosssection, it is to beunderstood that they may be round in cross-section. In the position shown in FIG. 7, the

blades are all held together by a thin wire 59 and have located centrally thereof an explosive charge 61 contained in a capsule which has an ignition fuse 63 extending therefrom. The explosive charge may be lead styphnate or, for example, Stabanate, while the fuse 63 may be a bi-metallic fuse as that described above or the fuse disclosed and claimed in my above mentioned copcnding application. When the low temperature fuse ignites by heat or flame, the charge is exploded and the resulting explosion causes the blades to be driven outward about their pivot pins until finally their sharpened edges 53a cut through the outer and inner containers. The blades 53 then rebound, due to their edges 53b striking the surface of the outer container leaving a plurality of clear passages for the escape of the freon to allow the freon to escape in all directions to extinguish flames over a large area. The extinguisher of FIGS. 7-10 may be connected electrically with an electrical system to allow the extinguishers to be fired remotely, if desired.

The fire extinguishers of the present invention may be employed in jet engine test cells, jet engine nacelles,

other aircraft compartments, as well as in boat engine compartments and gas heater closets. In both embodiments, a tab or connecting member l5e extends from the top end of the container 15 whereby the fire extinguisher may be hung from or attached to an object where desired.

I claim:

1. A fire extinguisher comprising:

a closed container,

a fire extinguishing gas under pressure located in said closed container,

an outer container encompassing tainer,

a plurality of spaced charge containers located next to said closed container and extending through said outer container and held between said closed and outer containers,

a shaped charge located in each of said charge'containers to cause perforation of said closed container when actuated toallow said fire extinguishing gas to pass out of said closed container through the perforations formed, and v a firetrain extending between said charge containers to cause all of said shaped charges to be actuated substantially simultaneously in the presence of temperature above an undesired level.

2. A fire extinguisher comprising:

a closed container, r,

a fire extinguishing gas under pressure located in said closed container,

an outer container encompassing said closed container, v

a plurality of blades, each having a sharp edge for perforating said outer and closed containers,

said blades being pivotally coupled to an end of said outer container and adapted to be moved to positions to perforate said outer and closed containers to allow said fire extinguishing gas to pass out of said closed container through the perforations formed,

holding means for normally holding said blades in positions to locate the cutting edges of said blades away from said containers,

explosive means located between said blades, when held by said holding means, for forcing said blades to positions to perforate said outer and closed containers when said explosive means is actuated, and

heat sensitive means for actuating said explosive means in the presence of temperature above an undesired level.

said closed con- 

1. A fire extinguisher comprising: a closed container, a fire extinguishing gas under pressure located in said closed container, an outer container encompassing said closed container, a plurality of spaced charge containers located next to said closed container and extending through said outer container and held between said closed and outer containers, a shaped charge located in each of said charge containers to cause perforation of said closed container when actuated to allow said fire extinguishing gas to pass out of said closed container through the perforations formed, and a firetrain extending between said charge containers to cause all of said shaped charges to be actuated substantially simultaneously in the presence of temperature above an undesired level.
 2. A fire extinguisher comprising: a closed container, a fire extinguishing gas under pressure located in said closed container, an outer container encompassing said closed container, a plurality of blades, each having a sharp edge for perforating said outer and closed containers, said blades being pivotally coupled to an end of said outer container and adapted to be moved to positions to perforate said outer and closed containers to allow said fire extinguishing gas to pass out of said closed container through the perforations formed, holding means for normally holding said blades in positions to locate the cutting edges of said blades away from said containers, explosive means located between said blades, when held by said holding means, for forcing said blades to positions to perforate said outer and closed containers when said explosive means is actuated, and heat sensitive means for actuating said explosive means in the presence of temperature above an undesired level. 